/**
 * Copyright 2010 The Apache Software Foundation
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.ipc;

/**
 * All custom RPC protocols to be exported by Coprocessors must extend this interface.
 *
 * <p>
 * <strong>Note that all callable methods must have a return type handled by
 * {@link org.apache.hadoop.hbase.io.HbaseObjectWritable#writeObject(java.io.DataOutput, Object, Class, org.apache.hadoop.conf.Configuration)}.</strong>
 * That is:
 * <ul>
 *   <li>a Java primitive type ({@code int}, {@code float}, etc)</li>
 *   <li>a Java {@code String}</li>
 *   <li>a {@link org.apache.hadoop.io.Writable}</li>
 *   <li>an array or {@code java.util.List} of one of the above</li>
 * </ul>
 * </p>
 */
public interface CoprocessorProtocol extends VersionedProtocol {
  public static final long VERSION = 1L;
}
